JPH0459528A - Sheet feeding device - Google Patents

Abstract

PURPOSE:To provide a sheet feeding device which prevents the defective feed of sheet material by matching a distance between sheet feed rollers on the cassette side with the width of a sheet material and selecting a plurality of sets of distances between the feed rollers on the body side. CONSTITUTION:The size of a sheet material P includes a maximum letter size, an A4 size, an executive size, and a B5 size. Even when feed rollers 7b and 7b on the cassette side are formed at a proper distance in a manner to match each size, the feed rollers 7b and 7b on the cassette side having an A4 size and a maximum letter size can cope with feed rollers 7aI and 7aIII on the body side. The feed rollers 7b and 7b on the sheet feed side having an executive size and a B5 size can cope with feed rollers 7aI and 7aII on the body side. Since, as note above, the sheet material P is conveyed by means of a feed roller pair having a distance approximately proper to the size of each sheet material P, defective conveyance of the sheet material is prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a small-sized image forming apparatus such as a copying machine or a printer, and more particularly to a paper feeding device for a small-sized image forming apparatus.

(n) PRIOR TECHNOLOGY In conventional small copying machines, printers, etc., as shown in FIG.
A small cassette-side roller f is provided between one-sided guide plates d and e provided on the cassette C side, and is opposed to this cassette-side roller f. A small-diameter body-side roller g is provided to form a paper feed roller pair f9g.

Note that the main body side roller g is a driving roller, and the cassette side roller f is driven by a spring member provided on the cassette side.
It is biased toward roller g. Further, i is a pickup roller provided on the main body side, and j is a separation claw provided at a corner of the cassette.

Further, k is a middle plate of the cassette C, which urges the sheet P upward and presses the sheet P against the pickup roller i.

Whether it is in the cassette C for the one-sided reference machine shown in FIG. 7(a) or in the center reference cassette C shown in FIG. 7(b), the rollers are A spacing of f9g was formed.

That is, the distance β1 and 1 from the end of the roller f to the end of the smallest size sheet Psin, and the distance from the end of the roller f to the largest size sheet P■aX! 22, there was a large difference between ρ and 122.

(C) Problems to be Solved by the Invention However, in the above conventional example, the minimum size sheet P
Even if the distance between the pair of paper feed rollers f1g with respect to the paper feeder is appropriate, there is no means for restraining the behavior of the sheet P near the edge for large-sized sheets, so a separating claw j is especially used. In this case, the sheet P that has passed through the separation claw j
The edges of the paper are often deformed, which has the disadvantage of causing a paper feeding failure when the sheet P enters the opening that is the connecting part with the main body a.

Therefore, the present invention adjusts the interval between the cassette-side paper feed rollers to the width of the stored sheet material, and also configures the interval between the main body-side paper feed rollers so that a plurality of sets can be selected.
It is an object of the present invention to provide a paper feeding device that does not cause sheet material conveyance defects.

(d) Means for Solving the Problems The present invention has been made in view of the above-mentioned circumstances, and for example, as shown with reference to FIG. 1 and FIG.
Insert the cassette (3) containing the
The sheet material (P) is loaded onto the main body side paper feed roller (7a) and sent out by the pickup roller (5).
and the cassette-side paper feed roller (7b) to feed the paper to the main body (1), the interval between the cassette-side paper feed roller (7b) is set to the cassette (3). It is characterized in that it is formed to match the width of the stored sheet material (P), and that the spacing between the main body side paper feed rollers (7a) can be selected from a plurality of sets.

Further, it is characterized in that the interval between the main body paper feed rollers (7a) corresponds to the interval between the cassette side paper feed rollers (7b) in conjunction with the mounting of the cassette (3).

(f) Function Based on the above configuration, the sheet material (P) is stored in the cassette (3), and the cassette (3) is installed in the image forming apparatus main body (1). Next, when you press the copy start button, the pickup roller (5) picks up the sheet material (P) on the top of the cassette (3).
Then, the sheet material (P) is passed through the main body side roller (
7a) and a cassette-side roller (7b) to feed the image forming apparatus main body (1). At this time, the sheet material (P) is held and conveyed by the main body side rollers (7a) that exactly match the width of the sheet material (P).

Note that the symbols in parentheses are just examples and do not limit the configuration in any way.

(F) Examples Examples of the present invention will be described below with reference to the drawings.

In FIG. 2, reference numeral 1 denotes a main body of an image forming apparatus, and a paper feed opening 2 leading to a transfer section is provided on the left side of the main body 1.

3 is a cassette which is inserted from the left side.

Further, 4 is an intermediate plate, and a sheet material P is placed on this intermediate plate 4, and is urged upward by an elastic member (not shown). Reference numeral 5 denotes a half-moon-shaped pickup roller that feeds out the upper sheet material P from the cassette 3. Then, the fed sheet materials P are separated by separation claws 6 provided at both corners of the cassette 3, and reach the paper feed roller pair 7a, 7b one by one along the paper feed guide plate 9. ing. and paper feed roller pair 7a,
The main body side paper feed roller 7a of 7b is a driving roller, the cassette side paper feed roller 7b is a driven roller, and the cassette 3
The roller 7a is pressed by a leaf spring 8 attached to the roller 7a.

Next, the pair of paper feed rollers 7a and 7b, which is the main point of the present invention, will be explained with reference to FIG.

FIG. 1 shows a cassette 3 based on one side.

In FIG. 1(a), the sheet material Pin is 85 inches (width 182 mm), which is the minimum width. Then, the cassette side paper feed rollers 7b, 7b are connected to this B5 type sheet material P.
It has an appropriate interval for win.

Further, the paper feed roller 7a on the main body side is provided with 7aI and 7an corresponding to the above-mentioned 7b and 7b, and further provided with 7aIII on the outside thereof.

In addition, in FIG. 1(b), a maximum letter-sized sheet material P wax is stored in the cassette 3, and the cassette side paper feed roller 7b
, 7b are arranged at appropriate intervals.

The main body side paper feed rollers 7aI and 7am correspond to each other.

Here, the size of the sheet material P is the maximum letter size width 2
15.9 Seals, A4 size width 210cm, executive size width! 84.15 ■ Otori, B5 size width 182 ■ Ugly.

Even if the cassette side paper feed rollers 7b, 7b are formed at appropriate intervals according to each size, the cassette side paper feed rollers 7b, 7b for A4 size and maximum letter size are opposed to the main body side paper feed rollers 7aI, 7am. The executive size and B5 size cassette side paper feed rollers 7b, 7b can be opposed to the main body side paper feed rollers 7al, 7a.

In this way, since the sheet materials P are conveyed by the paper feed roller pair with a substantially appropriate interval for the size of each sheet material P, no defective conveyance of the sheet materials occurs.

Next, another embodiment will be described with reference to FIG.

In this embodiment, the above-mentioned FIGS. 1(a) and (b)
The main body side paper feed rollers 7aII and 7am of the embodiment shown in are combined into one roller 7an'.

The effect is the same as in the previous embodiment.

Next, still another embodiment will be described with reference to FIG.

FIG. 4 shows the cassette 3 with a central reference.

Therefore, as shown in FIG. 4(a), the main body side feed rollers 7an and 7aI[I correspond to the small sheet material P, and as shown in FIG. 4(b), This corresponds to the paper feed rollers 7aI and 7alV on the main body side.

Further, the main body side paper feed roller 7'a is the above-mentioned 7aI.

n, 7am, and IV are each integrated, and the effect is the same as above.

Next, another embodiment will be described with reference to FIG.

In this embodiment, a case of one-sided reference is shown.

The cassette-side paper feed rollers 7b, 7b are formed at intervals appropriate to the width of the sheet material P stored in the cassette 3.
One of the paper feed rollers 7a on the main body side shown in FIG.
It is formed integrally with the flange portion 12 via a spline or key between the shaft 10 and is movable only in the axial direction of the shaft 10, and is in contact with the inside through a compression coil spring 13. Forced outward against one roller 7a,
It is stopped by a stopper 14 provided on the shaft 10.

Further, as shown in FIG. 5(a), a cam 15 is formed on the cassette 3 so as to be able to engage with the flange portion 12 from the outside.

Therefore, when the cassette 3 is moved to the right and attached to the main body 1, the left end portion 15a of the cam 15 causes the flange portion 1 to
2 is positioned, and the paper feed roller 7a, which is integrated with this flange portion 12, is positioned at a position corresponding to the cassette side paper feed roller 7b.

In this way, the sheet material P is moved at appropriate intervals by the pair of rollers 7a,
7b can be fed.

This effect is the same as that of the embodiment described above, and the distance between the roller pairs can be adjusted even for various sheet materials whose widths are not standardized.

(G) As described in detail, according to the present invention, the intervals between the paper feed rollers on the cassette side are formed to match the width of the sheet materials stored in the cassette, and the intervals between the paper feed rollers on the main body side are formed in a plurality of ways. Since the pair can be selected, the pair of paper feed rollers can be set at an appropriate position from the end of the sheet material regardless of the size of the sheet material, which has the effect of preventing poor conveyance of the sheet material.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a paper feeding device as an embodiment of the present invention;
FIG. 1(a) shows the condition for a narrow sheet material, and the first
Figure (b) shows a state for a large sheet material, Figure 2 is a side view of the paper feed section of a small image forming apparatus embodying the present invention, and Figures 3 (a) and (b) depict another example. Plan view shown, No. 4
Figures (a) and (b) are plan views showing still another embodiment, Figure 5 is a plane view of another example, Figure 5 (a) shows the cassette side paper feed roller, Figure (b) shows the paper feed roller on the main body side, Figure 6 is a side view of the paper feed section of a conventional small image forming apparatus, and Figure 7 (a) shows the relationship of the paper feed roller to the narrow sheet material. FIG. 7(b) is a plan view showing the relationship of the paper feed roller to the large sheet material. 1... Image forming apparatus body 3... Cassette 5.
...Pickup roller 7a...Main body side paper feed-
Roller 7b...Cassette side paper feed roller, P...
・Sheet material

Claims (1)

[Scope of Claims] 1. A cassette containing sheet material is installed in the main body of an image forming apparatus, and the sheet material sent out by a pickup roller is transported by the main body side paper feed roller and the cassette side paper feed roller. In the paper feeding device that feeds the paper to the main body using a pair of paper feed rollers, the spacing between the cassette-side paper feeding rollers is formed to match the width of the sheet material stored in the cassette, and the spacing between the main body-side paper feeding rollers is formed to match the width of the sheet material stored in the cassette. A paper feeding device characterized in that a plurality of sets can be selected. 2. The paper feeding device according to claim 1, wherein the spacing between the main body side paper feeding rollers corresponds to the spacing between the cassette side paper feeding rollers in conjunction with mounting of the cassette.